The present invention relates to a solenoid valve apparatus.
A solenoid valve apparatus of this type has been proposed in the related art. The proposed solenoid valve apparatus includes: a solenoid valve that is disposed in a hydraulic circuit for switching a friction engagement device (a clutch) of an automatic transmission installed in a vehicle ON and OFF in order to regulate an oil pressure input from a hydraulic pump driven by power from an engine and output the regulated oil pressure to the clutch; a selector valve that is interposed in an oil passage connecting the solenoid valve to the clutch in order to connect and disconnect the oil passage selectively; and an electromagnetic pump that is connected to the oil passage connecting the selector valve to the clutch via a check valve in order to supply working oil to the clutch in accordance with repetitive excitation and non-excitation of an electromagnetic coil (see Japanese Patent Application Publication 2008-180303, for example).